A single chitosan-based fluorescent sensor for the discriminant analysis and quantitative detection of bisulfite and...

The excessive use of bisulfite (HSO₃^-) and oxytetracycline (OTC) not only poses a significant threat to the environment, but also leads to a multitude of health issues in humans via the food chain. Consequently, there is a pressing need to develop an efficient method for the rapid, convenient, accurate, and real-time detection of HSO₃^- and OTC in food products and environmental water. In this study, we investigated a novel chitosan-based fluorescent sensor, CABA - CNF, which enabled a dual response to HSO₃^- and OTC through distinct emission channels. Moreover, due to the signal amplification effect, the polymeric sensor CABA - CNF exhibited low detection limits of 13 nM for HSO₃^- and 19 nM for OTC, along with rapid response times of 10 s and 6 s, respectively. Furthermore, by employing a smartphone-based sensing platform, the sensor CABA - CNF successfully quantified HSO₃^- and OTC in actual food and water samples with high accuracy and reliability.